Control device for mixing-machines



E. H. LICHTENBERG. CONTROL DEVICE FOR MIXING MACHINES.

APPLICATION FILED MAR. 29. I915.

Patented Nov. 11, 1919.

I 2 SHEETSSHEET I.

E. H. LICHTENBERG.

CONTROL DEVICE FOR MIXING MACHINES.

APPLICATION FILED MAR. 29. I915.

Patented Nov. 11, 1919.

2 SHEETS-SHEET 2.

I I I I 1 1 l I I 1 n I I UNITED STATES PATENT GFFICE.

ERICH H. LICHTENBERG, OF MILWAUKEE, WISCONSIN, ASSIG-NOR KOEHRING MACHINE COMPANY, OF MILWAUKEE, WISCONSIN.

CONTROL DEVICE FOR MIXING-MACHINES.

Specification of Letters Patent.

Patented Nov. 11, 1919.

Application filed March 29, 1915. Serial N 0-. 17,816.

To all whom it may concern Be it known that I, Enron H. LIcHTE-N- BERG, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of \Visconsin, have invented certain new and useful Improvements in Control Devices for Mixing-Machines, of which the following is a specification.

This invention has to do with the art of concrete mixing machines, and mixing machines generally.

In its complete embodiment the invention is an attachment for concrete mixers comprising automatic signaling; counting, and

mixer discharge controlling means. While the invention includes the combined instrumentalities above mentioned, I wish it to be understood that I consider the means forming the attachment not only combinatively novel, but so far as I am advised the devices going to make up such means are new, each in itself, and capable of individual use, as will more clearly appear hereinafter.

To fully comprehend the advantages of my invention I refer briefly to the operation of well known types of concrete mixing machines. In such machines suitable mixing means, as a power driven mixing drum or receptacle, is employed; loading means for the drum, of any. suitable nature, are used; and, necessarily some device of one kind or another is employed to control the discharging of the contents of the mixer after completion of mixing operation. These mixers are ordinarily used for the admixture of cement, sand, and gravel, or such materials, and it is an absolute requirement for effective andlasting construction work, whether such be building or other erection, laying of pavements, or-the like, that a proper admixture of the materials be compelled.

In the employment of ordinary concrete mixing machines it is customary in respect to their use on Government and other contract work to rigidly supervise the operation of the machines to make sure that proper admixture of the plastic materials is performed; in factinspectors are regularly employed for this particular work to guard against both carelessness and fraud, the latter arising commonly as an incident to contractors forcing both workmen and machines to such an extent that sufficient time for mixing is not allowed.

lVith the foregoing in view this invention provides a means to signal or indicate automatically, after char 'ng or loading the mixer with the materia s to, be mixed, when the minimum time required for completion of the mixing operation has elapsed. The signaling means, furthermore, is susceptible of adjustment to admit of its application to different types of machines, and to accord with different sized batches of materials handled. In addition said means is protected against unauthorizedtampering, a necessary expedient to make it effective.

Supplementing the advantages afforded by the signaling means, are those derived from utilizing cooperative locking means, whereby the discharge of the mixed materials previous to complete admixture is ab solutely guarded against,

From the viewpoint of the contractor or owner of the machine, it is desirable to have a device for counting the operations of loading the mixer so that the work of the machine each day, or any. determinate time, may be readily ascertained. As before premised, special means for the last named purpose have been devised and combined with the other instrumentalities of this invention, all of which will be now described in detail on reference to the accompanying drawings, in which 2- Figure 1 is a general view in side elevation of a street paving concrete mixer having the invention applied thereto.

Fig. 2 is a fragmentary and diagrammatic view showing the signaling mechanism, the counter and controlling connections forming the essential features of the attachment means comprising the invention.

Fig. 3 is a cross sectional view taken vertically through the casing which incloses the signal bell, governor mechanism and the counter and which casing is locked closed by any suitable means. This view is taken on the line '33 of Fig. 2.

Fig. 4 is a cross section on the line 4-4 of Fig. 2.-

Fig. 5 is a diagrammatic view showing the control arrangement employed when it is not desired to employ the lock for the discharge chute.

Fig. 6 is a detail view showing more clearly the circuit closing means controlled by the governor.

Fig. 7 is a detail view showing more clearly the connection between the shaftof the discharge chute and the operating handle, the latter illustrated in dotted lines.

The term signal as used herein is intended to includean indicator, or any equivalent device, for advising ither visibly or audibly, or otherwise, of the completion of the mixing operation.

Avery brief description of the concrete mixing machine to which the attachment of this invention is applied will suflice, since th particular type of such machine is immaterial to the invention which has a wide range of applicability to various kinds of mixing machines irrespective of the specific form of the. mixing mechanism per sea.

In the drawings is illustrated what is known as a street paving mixer, the same embodying a suitable truck A to render the machine portable, a mixing drum B mounted on the truck for rotation in effecting the mixing ope-ration, and a loading means for the drum including a charging bucket or skip C. The bucket or skip G is adapted to be. raised by means of a cable D designed to be operated by suitable power means and said bucket C is supported on the frame of the machine by a pivoting bracket E. The materials may be dumped into thebucket 0 when the latter is in the full line position shown in Fig. 1 and by elevating the bucket to the dotted line position its contents will be fed into the mixing drum B, this being ordinarily done while the drum is rotating. To discharge the drum B I contemplate the employment of a discharge chute F of the type shown in United States Letters Patent to Philip A. Koehring, Number 1,126,487 issued January 26th, 1915, said chute being tiltable from a position in which it inclines into the drum B to a position in which it inclines clownward and outward from the. discharge opening at the discharge end of said drum. In

the latter position the chute F will discharge the contents of the receptacle B, the material discharged being adapted to be carried off to a suitable point of deposit by means of a boom and bucket. attachment includ-' ing the boom G and bucket H. A shaft is connectedwith the discharge chute F and is operable by handle I whereby to effect the tilting of the chute into discharge and nondischarging positions. Any suitable means to discharge the mixed materials may be used within the purview of my invention.

The signaling, counting and controlling attachment embodying this invention includes a suitabl casing or box l secured in a suitable position on the frame of the machine, preferably adjacent to the bracket E. This box contains an ordinary electric bell 2 forming an audible signal, a counter 3 and a governor 4. The governor 4 may be of any desired type but is comprised as shown of a standard formed with horizontal upper and lower arms 5 and 6 respectively, to-

ing pin gether with a zigzag or tortuous groove 7, formed on an arc as seen in the cross section of Fig. 4, the latter being produced in one side of said standard. The arms 5 and 6 are vertically apertured so as to receive therethrough a sliding metal stem 8 to the upper end portion of which is secured a cross bar 9. On its ends, which are preferably bent downwardly, the cross bar 9 carries the adjustable weights 10, the parts 9 and 10 forming a gravitating and slightly rotative governor member tending to force the stem 8 downward and hold it in a posi-' tion at the lower extreme of its free vertical movement upon the standard 4. The stem 8 carries at a point intermediate the arms 5 and 6 of the standard 4, a laterally movable pin 11 the opposite ends of which are headed so as to prevent its displacement from the stem. The pin 11 is freely slidable transversely relative to the stem 8, through an opening formed in the latter and one end of the stem 11 is adapted to engage in the groove 7 of the standard. 4. The engage ment of the pin 11 in the groove 7 is caused by raising the stem 8 in a manner to be hereinafter described, the outer end of the pin 11 striking a curved cam 5 on the arm 5 and being forced laterally into the desired engagement with the groove 7. Owing to the provision of the governor member 9, 10 once the pin 11 engages the groove 7 and the stem 8 is left free to gravitate, the gravitating movement of the stem will start and the speed of such movement is variable by the 100 adjustment of the weights 10 toward and from the point of connection of the memher 9 with the stem 8, the extent of rotative swing of the weights 10 varying according to the adjustment. Obviously during its 105 downward movement owing to the cooperation-of the pin 11 With the groove 7 the stem 8 and parts 9 and 10 have artial rotative movement in opposite directions.

The counter 3 may be of any conventional type and is intended for the purpose of registering the number of batches of mate rials fed into the mixing drum B by means of the skip or loading bucket C. The counter 3 has an actuating arm 3 at one end of the same directly actuating the units wheel of the counter, and there will be employed any suitable transfer devices intermediate. the units and tens and other registering wheels of higher denominations.

A lever 12 is pivoted at a point within the box 1, preferably on the rear Wall of the latter and its inner end engaging an offstand- 13 at the lower extremity of the stem 8. Said lever 12 extends through a side of the box 1 and has connected therewith an actuating bar 14 which extends upward from the point of pivotal connection of its lower end with the outer extremity of the lever 12, to a point adjacent to the pivot of the pivoting bracket E. .The object of this arrangement of the bar 14 is to enable the bracket E to bump against or impinge the upper end of the bar 11 each time the loading bucket C is hoisted to supply a batch of material to the mixing drum B. Obviously the impingement of the part E with the bar 14: depresses the lever 12 at its outer end, correspondingly raises the inner end of the lever together with the stem 8 and sets the I governor 4 to operating. The object is to cause the governor at the end of its operation to close the circuit including the bell 2 whereby the latter will be sounded to afford an audible signal. The operation of the governor e is timed so that when it is set in motion by the loading means or bucket C there will be a predetermined period of time elapsed before the signal 2 sounds. This elapsed time is at least the minimum time required for the mixing; of the batch delivered to the drum B by the bucket C.

As a general thing, under actual conditions of use, the signaling means is intended to be susceptible of adjustment for operation after the expiration of the time fixed for the mixing operation, ranging from three seconds to three minutes. As suggested, the time is dependent upon the size or capacity of the mixing drum itself, or the amount of materials that may be fixed as the batches to be mixed, for a predetermined operation of the machine, say in accordance with certain specifications. Adjustment of the signal for operation of different elapsed times is controlled by the corresponding adjustment of the weights 10 in a mannerdescribed hereinbefore.

The circuit connections used are simple, ircuit wires 15 and 16 leading to separated contacts 15 and 16', contact 15 being on the block 17 arranged in the box 1 beside the stem 8, and the other contact 16 being carried by the governor at the standard of which is of metal. The wire 16 leads from the contact 16 to the hell 2 and a suitable wire 18 leads from the bell 2 to the battery 19. The circuit wire 15 leads to the battery 19 also but has connected up in its length the electro-magnet 20. Associated with the magnet 20 is an armature lock 21 said lock being cooperative with a projection 22 on the controlling shaft 23 which carries the handle I by which the discharge chute F is tilted into discharging or non-discharging positions.

General operation of machine.

Bearing in mind that adjacent to its point of pivotal support the lever 12 has a member 12' to engage the actuating arm 3' of the counter 3 after tripping the counter each time the outer end of the lever 12 is depressed the operation of the entire mechanism will be clearly understood on reference to the following description; Assuming th t the parts are in the full line positions shown in Fig. 2 when the bucket C is loaded the operator of the machine will cause elevation of the bucket by suitable controlling means. As the bucket reaches its uppermost position shown in dotted lines in Fig. 1 its contents will be discharged into the drum B and the actuating bar 14 will have been impinged and operated by the pivot bracket E. The above causes the lever 12 to raise the stem 8 of the governor 4 and the pin 11 engages the cam 5 and is forced laterally into engagement with the groove 7. The bucket (1 returns to its downward receiving position and the governor means including the parts 8, 9 and 10 are permitted to gravitate, the time required for said members to complete their full downward movement depending upon the adjustment of the weights 9 and 10. As the stem 8 reaches the lower extreme of its movement the pin 11 engages a cam 6 on the governor t, is forced outward from the groove 7 and leaves the stem 8 free to be quickly forced upward the next time the bucket C is raised and the bracket E impinges the bar 14. When the stem 8 approaches said lower extreme of its movement 8 has passed the block 1'? the circuit is broken and the parts restored, the signal ceasing operation. The brush 8 has insulation on its upper side so that on its onward movement the circuit will not be closed. Said brush is pivoted to the stem 8 by a spring hinge 8 and swings downward on the upstroke of the stem 8. The signal bell 2 is caused to sound while the parts 8' and 17 are 1ncontact, and advises the operator of the machine that sufiicient time has elapsed for proper admixture of the materials previously fed into the drum B, whereupon the operator may actuate the handle I, and turn the chute F into adischarging position. The closing of the circuit as above described not only causes the operation of the audible signal 2 but energizes the magnet 20 thereby attractlng the armature 21 and disengaging the locking portion of said armature from the projection 22. \Vere it not for this disengagement it will be obvious that the operator would not be able to move the chute F to discharge the contents of the drum B.

The provision of the members 2 and 21 affords a double precaution or check against the operation of discharging the contents of the mixing drum previous to the proper admixture of the materials therein contained. I contemplate within the purview of my invention the employment of the parts 2.

materials is able to supervise the proper operation of the mixer even though he be some distance away from the place where the machine is located. The operator of the machine is of course primarily advised of the completion of the mixing operation, by the signal 2 and also advised that the shaft 23 is free for operation owing tothe fact that said shaft is unlocked simultaneously with the sounding of the signal 2. During the operation of the lever 12 the counter 3 is actuated and registers each time a batch of mate rials is loaded into the drum B.

It is contemplated that the casing 1 shall be supplied with a suitable door to enable access to the mechanical devices inclosed thereby, and said door shall be locked by any substantial devices whereby to prevent unauthorized access thereto.

Fig. 4 illustrates the circuit wires and the discharge chute handle I in their relation employed when the lock 21 is dispensed with as may be desirable under some conditions.

Having thus described the invention, what is claimed is 1. In combination, a mixing machine comprising a mixing device, means to control its operation, and means adjustable according to the time required for mixing a batch of material by operation of said mixing device to automatically signal a predetermined time of completion of the mixing operation of such machine.

2. The combination, with a mixing ma.- chine comprising a mixer, means to discharge the same, and charging mechanism, of a signal adapted to indicate when the mixer has completed its operation to effect thorough admixture of the materials operated on thereby, and coacting instrumentalities between the signal and the charging mechanism for controlling the signal from said mechanism.

3. A mixing machine, comprising charging and discharging means, means for operating said machine, and locking means controlled by the charging means to prevent operation of the discharging means until after a given period of operation of the mixer.

4:. A mixing machine, comprising charging and discharging means, means for operating said machine, locking means to prevent operation of the discharging means until after a given period of operation of the mixer, and automatically operating means to cause the locking means to perform its locking function.

5. A mixer, discharge means therefor,

means for charging the mixer, a signal to indicate completion of a mlxing operation of the mixer, and means to control the set-- ting of the signal operable by the charging means.

6. The combmation, with a mixing machine comprising a mixer, means to d1scharge the same, and charging mechanism, of a signal adapted to indicate when the mixer has completed its operation to effect thorough admixture of the materials operated on thereby, coacting instrumentalities between the signal and the charging mechanism for controlling the signal from said mechanism, and lock means for the means to discharge the mixer controllable by the signal mechanism.

7. The combination, with a mixing machine comprising mixing mechanism, means to discharge the mixed materials from said mechanism, and charging means for said mixing mechanism, of lock means to prevent operating of the discharge means, and coacting instrumentalities between the charging means and the lock means to control the action of the latter by the charging means.

8. A mixing machine, com-prising charging and discharging means, means for operating said machine, locking means to prevent operation of the discharging means, until after a given period of operation of the mixer, and automatic means controlling the locking and release actions of said looking means, so as to control operation of the discharging means during the operation of the mixing machine.

9. A mixing machine, comprising charging and discharging means, means for operating said machine, locking means to prevent operation of the discharging means, until after a given period of operation of the mixer, and common means automatically controlling both releasing and re-locking action of said locking means, during the operation of the mixer.

10. In combination, a mixing machine comprising a mixer, discharging and charging devices therefor, means for operating the mixer, and means controlled by the charging device to govern the operation'of the discharging device.

11. The combination, with a mixing machine comprising mixing mechanism, means to discharge the mixed materials from said mechanism, and charging means for said mixing mechanism, of lock means to prevent operating of the discharge means, and means operable bythe charging means to release the lock means and thereby permit operation of the said discharging means.

12. In combination, a mixer, means for operating the same, a charger therefor, and means automatically controlled by said charger for positively preventing the discharge of said mixer until after a given number of operations of said mixer.

13. In combination, a mixing machine comprising a mixing device, means for supplying materials to said device, a signal to indicate a predetermined condition of the materials acted on by the mixing device, a governor controlling the operation of said signal, and means intermediate said supply means and the governor for setting the latter for operation to in turn operate the signal.

14. In combination, a mixing machine including a mixing device, means for operating said device, discharge means for said device, a lock for normally preventing discharge action of said discharge means, a governor, loading means for the mixing device, and means intermediate said loading means and the governor to set the latter in operation to subsequently cause release of said lock means.

16. In combination, a mixing machine including a mixing instrumentality and controlling mechanism forming an adjunct for said mixing instrumentality, a signal associated with the mixing instrumentality and adapted to indicate the time of completion of the mixing operation of the latter, and means intermediate the controlling mechanism aforesaid and said signal for effecting automatic operation of the latter for the purpose described.

16. In a. mixing machine, the combination of a mixer, means for operating the same, means for admitting material therein, means for discharging the material, and means for :locking the discharger; with a charger, and

controlling means adapted to be st by the charger and then operate to automatically release the discharger after the material is admitted into the mixer, and the discharging means has been kept locked until the mixer has performed a predetermined number of operations.

17. In combination, a mixer adapted to receive a charge of materials to be mixed, means whereby said materials may be discharged from the mixer, means positively locking the discharge means against dis-' charge operation, controlling means for said locking means for compelling a suflic-ient number of operations of the mixer to insure proper admixture of the materials received thereby befofi sa'rd materials can be discharged, and to hen release the discharge means from the locking means, and means for charging the mixer governing the action of said controlling means.

18. In a concrete mixing machine, the combination of a mixer, a charging device therefor, a discharging device for said mixer, lock means normally positively preventing operation of one of said devices, and means controlled by the other device for governing release action of said lock means to enable the device locked thereby to be operated.

19. The combination, with a mixing machine comprising mixing mechanism, manuof the said means governs the operation of the lock means.

20. In combination, a mixing machine including a mixing device, means for operating said, device, discharge means for said device, a lock for preventing operation of said discharge means, a governor adapted to determine the time of completion of a mixing operation of the mixing device, loading means for the mixing device, and means intermediate said loading means and the governor to control the operation of the latter to subsequently cause release of said locking means only when the time of complete mixing action of the mixing device has elapsed.

21. In combination, a concrete mixing machine comprising a mixer, means for operating the same, and discharging means there for, locking means for the discharging means to prevent operation thereof until a predetermined time required for mixing has elapsed, automatic controlling mechanism for the locking means, a casing inclosing said controlling mechanism, and means to prevent unauthorized access to the controlling mechanism in the casing.

22-. In combination, a concrete mixing machine comprising a mixer, means for operating the same, and discharging means therefor, locking means for the discharging means to prevent operation thereof until a predetermined mixing period has elapsed after charging of the mixer, a controller for the locking means adjustable to conform with different required mixing periods and operable as an incident to the charging operation, and means to prevent unauthorized ERICH H. LICHTENBERG.

Witnesses:

W. PRESTER, WM. A. MEYER. 

